1. Field of the Invention
The present invention relates to a lighting device and a lighting fixture having a plurality of light sources.
2. Description of Related Art
Lighting devices in which light emitting diodes or other such light emitting devices are used as the light source have been proposed. Also, lighting devices or lighting fixtures are known in which the light from a plurality of light sources is superposed on the irradiation target. For example, in a clinical use, lighting fixtures are used to illuminate the afflicted part of a patient (the irradiation target) by superposing light emitted from light sources on this site. This lighting fixture may be configured such that light irradiation units each comprising a light source and a reflecting mirror that reflects the light of this light source are arranged.
There has also been proposed a stacked type of light emitting diode device in which a plurality of the above-mentioned light irradiation units are installed on those optical axis (for examples Patent Literature JP2006-318995A). This light emitting diode device is formed by connecting a plurality of reflective light emitting diode units that are respectively formed by placing a light emitting diode and a dichroic mirror, by means of a connection member made of an electric insulating material.
With above mentioned conventional lighting devices or lighting fixtures, however, when the distance between the irradiation surface and the light emission component is changed, this may result in mismatched of the light beams obtained from each of the light emission units, which may be a problem in that the color of the light obtained at the irradiation surface is mismatched or uneven. Also, with the device in the above Patent Literature, units having the same size each other are stacked in the optical axis direction, so the size of the device may be enlarged in the depth direction.